A comparison of conventional and new rubber dam systems in dental practice.

OBJECTIVE: Rubber dam is an important tool in dentistry-in the past as well as today. As a result of a lack of acceptance of the conventional system, introduced by Barnum in 1869, new systems were developed (eg, OptraDam® by Ivoclar Vivadent AG, Schaan, Liechtenstein). This system was advertised as being very comfortable and easy to use, without distracting clamps. The aim of this study was to investigate if a new rubber dam system would be better accepted by patients and dentists than the conventional one. MATERIALS AND METHODS: Two hundred patients from the Department of Conservative Dentistry and Periodontology received at least one treatment with the conventional rubber dam (Dental Dam, Coltène Whaledent, Langenau, Germany) and one with the new rubber dam (OptraDam®, Ivoclar Vivadent). Staff/students and patients were asked to complete questionnaires with regard to the advantages and disadvantages of the particular system after every treatment. RESULTS: Among patients, students, and dentists in the dental school environment there is a high degree of acceptance of rubber dam in general. During the study there were only very few situations in which neither of the systems could be used. The conventional rubber dam was preferred by all patients, students, and dentists (p<0.0001). CONCLUSION: Our study confirms that there is a high degree of acceptance of the rubber dam when it is compulsory to use. The reasons for the refusal during the daily workload of a practice remain unclear, but appear to be independent of the material or design available. A new design does not necessarily imply better acceptance.

Nonsurgical endodontic management of a double tooth: a case report.

AIM: To present a case with various morphological irregularities requiring root canal treatment and to discuss the problems and options for orthograde root canal treatment. SUMMARY: Root canal treatment of a double tooth presenting with an acute alveolar abscess is described. The anatomical variations of this tooth included double tooth, dental invagination, incomplete apical closure, three root canal systems and an internal lacuna. The tooth was treated nonsurgically with orthograde root canal treatment resulting in nearly complete radiographic apical repair after 4 years. KEY LEARNING POINTS: *Double teeth occur infrequently and may be distinguished from fusion, gemination, concrescence and dental twinning. *Several malformations may be present in a single tooth. *Orthograde root canal treatment may be an adequate treatment option even in teeth with a complex internal anatomy.

Guidance of shrinkage vectors vs irradiation at reduced intensity for improving marginal seal of class V resin-based composite restorations in vitro.

This study evaluated the influence of radiation intensity on polymerization of a resin-based composite (RBC) and compared the influence of guidance of shrinkage vectors vs irradiation at reduced light intensity on the marginal seal of Class V RBC restorations in vitro. The degree of cure was studied indirectly by measuring the Vickers hardness (1.96 N, 30 seconds) at the bottom of disc-shaped specimens 2 mm in height at different periods of time after light irradiation. After one hour, irradiation using a high-intensity curing light (Heliolux GTE, Vivadent, 600 mW/cm2) [HICL] from close distance for 20 seconds, 40 seconds or 60 seconds or a low-intensity curing light (Vivalux, 250 mW/cm2) [LICL] from close distance for 60 seconds produced higher hardness values compared to 20 seconds or 40 seconds using the LICL or using the HICL from a distance of 10 mm. After three and 24 hours, higher hardness was observed for all irradiation protocols. After 24 hours, only specimens irradiated by the HICL for 20 seconds or 40 seconds from 10 mm distance featured significantly lower hardness compared to the remaining curing modes. The influence of different irradiation strategies on marginal seal of Class V RBC restorations was evaluated in vitro using dye penetration after water storage (60 days, 37 degrees C) and thermocycling (2500 cycles 5 degrees-55 degrees C). The HICL produced more dye penetration than the LICL. Placing the light tip directly over or 10 mm above the center of the cavity ("standard irradiation, ["distance irradiation"]") resulted in similar penetration values. In contrast, positioning the light tip apical to the cervical margin and moving it slowly to the center of the cavity ("cervical start irradiation") compromised the marginal seal.

Comparison of photo-activation versus chemical or dual-curing of resin-based luting cements regarding flexural strength, modulus and surface hardness.

This study investigated the efficiency of chemical activation of dual-cure resin-based luting cements as compared with light- and dual-curing. Curing was performed by (i) mixing base and catalyst without subsequent irradiation (chemical curing=CC), (ii) mixing base and catalyst with direct irradiation (dual-cure=DC) or with (iii) irradiation through 2.5 mm of leucite-reinforced glass-ceramics (IPS Empress, Ivoclar) (dual-cure through porcelain=DCtP), (iv) using only the base paste with direct irradiation (light-curing=LC) or with (v) irradiation through porcelain (light-curing through porcelain=LCtP). Specimens of four fine-hybrid DC resin composites and one self-cure hybrid resin composite (only CC) were prepared and tested after 24 h for flexural strength, modulus of elasticity (ISO 4049) and surface hardness (Vickers). For all materials and parameters, dual-curing produced higher values than LC, even when irradiation was performed through porcelain. Following self-curing without photo-activation, flexural strength was 68.9-85.9%, the modulus 59.2-94.5% and Vickers hardness 86.1-101.4% of the corresponding values obtained by dual-curing with direct irradiation. Light-curing through porcelain as compared with direct irradiation reduced the values for most parameters and materials. In contrast, dual-curing maintained flexural strength for all, the modulus for three and the hardness for one of the materials. The mechanical properties of the self-curing resin cement ranged between those of the DC materials.

[A retrospective in vivo study of Sonicsys approx restorations]. / Retrospektive In-vivo Untersuchung von Sonicsys-approx-Füllungen.

The purpose of this retrospective study was to determine the longevity and quality of Class II resin composite restorations with Sonicsys approx inserts placed in private practice. In 79 patients 213 composite restorations with margins in enamel and in dentin were evaluated clinically using a modified version of established USPHS-Criteria. The mean time in clinical service was 18+-8 months. The majority of the restorations investigated were rated as "good" (Alpha) or "clinically acceptable" (Bravo). In more than 90% sufficient proximal contact points were evaluated. Seven restorations had no contact to their adjacent tooth. Only one failed after an average period of 18 months in clinical service because of loss of the ceramic insert and was replaced. It is concluded that the composite restoration in combination with Sonicsys insert is an appropriate system for the restoration of Class II lesions in premolar and permanent molar teeth.

[In vivo study of small class II composite fillings]. / In-vivo-Untersuchung von kleinen Klasse-II-Kompositfüllungen.

This clinical trial aimed at studying the medium term performance in routine clinical practice of drop-shaped Class II resin composite restorations. 111 preparations were completed with the Sonicsys micro-tips (KaVo) and filled with either of two light-cured composites (Tetric Flow, Tetric Ceram, Vivadent, Schaan, Liechtenstein) by 11 dentists in a university clinic. The restorations were evaluated after half a year and then annually, using the US Public Health Service criteria. After one to three years of service nearly all restorations were clinically successful and acceptable for continued use. In four cases, incomplete caries excavation was the cause of failure. We conclude that the drop-shaped Class-II-resin composite restoration should be considered a routine operative treatment for small proximal lesions in posterior teeth.

[In vitro study of marginal quality of small approximal composite fillings]. / In-vitro-Untersuchung zur Randqualität von kleinen approximalen Kompositfüllungen.

The aim of the study was to compare different preparation methods and filling techniques for class II microcavities in vitro. The following methods were evaluated: Sonicsys halftorpedo, Sonicsys halfsphere, Sonicsys approx, Siplus, Piezo cavity system and rotating finishing bur. Every cavity type was obturated with a flowable (Tetric flow) and with a hybrid composite (Tetric ceram). One group consisted of prefabricated ceramic inlays (Sonicsys approx) and one group was filled with a three-site light curing technique. This resulted in 128 composite fillings. The evaluation of the quality of the margins under the SEM demonstrated a statistically significant higher percentage of perfect margins for Siplus compared with the PCS-System (88% versus 58% perfect margins). Marginal adaptation before and after thermocycling demonstrated the following results: Bewelled margins showed in general better adaptation than box-shaped cavities. Similar results were found for normal and flowable composites. Microcavities with occlusal access prepared with the sonicsys halfsphere showed in general better marginal adaptation in comparison to the other methods tested. It was concluded that simple obturation techniques can lead to a stable adaptation of the margins.

Comparison between a plasma arc light source and conventional halogen curing units regarding flexural strength, modulus, and hardness of photoactivated resin composites.

The plasma arc curing light Apollo 95 E (DMDS) is compared to conventional curing lights of different radiation intensities (Vivalux, Vivadent, 250 mW/cm2; Spectrum, DeTrey, 550 mW/cm2; Translux CL, Kulzer, 950 mW/cm2). For this purpose, photoactivated resin composites were irradiated using the respective curing lights and tested for flexural strength, modulus of elasticity (ISO 4049), and hardness (Vickers, Knoop) 24 h after curing. For the hybrid composites containing only camphoroquinone (CQ) as a photoinitiator (Herculite XRV, Kerr; Z100, 3 M), flexural strength, modulus of elasticity, and surface hardness after plasma curing with two cycles of 3 s or with the step-curing mode were not significantly lower than after 40 s of irradiation using the high energy (Translux CL) or medium energy conventional light (Spectrum). However, irradiation by only one cycle of 3 s failed to produce adequate mechanical properties. Similar results were observed for the surface hardness of the CQ containing microfilled composite (Silux Plus, 3 M), whereas flexural strength and modulus of elasticity after plasma curing only reached the level of the weak conventional light (Vivalux). For the hybrid composites containing both CQ and photoinitiators absorbing at shorter wavelengths (370-450 nm) (Solitaire, Kulzer; Definite, Degussa), plasma curing produced inferior properties mechanical than conventional curing; only the flexural strength of Solitaire and the Vickers hardness of Definite reached levels not significantly lower than those observed for the weak conventional light (Vivalux). The suitability of plasma arc curing for different resin composites depends on which photoinitiators they contain.

Interleukin-1 haplotype and periodontal disease progression following therapy.

The purpose of this study was to assess the prognostic value of the IL-1 haplotype on the progression of periodontal disease following therapy. 48 adult patients with untreated periodontitis harboring Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis were randomly assigned to receive full-mouth scaling alone (control) or in combination with systemic metronidazole plus amoxicillin and supragingival irrigation with chlorhexidine digluconate (test). All patients received supportive periodontal therapy at 3 to 6 months intervals. In 33 patients, lymphocyte DNA was analyzed for polymorphism in the IL-1A gene at position -889 and IL-1B gene at position +3953. Overall, 16 of 33 patients (7 of 17 test and 9 of 16 control) carried the IL-1 haplotype. 2 years following initial periodontal therapy, no differences in the survival rates of sites or teeth not exhibiting probing attachment loss of 2 mm or more compared to baseline, were found between patients who tested positive (85% sites, 53% teeth) and patients who tested negative (89% sites, 56% teeth) for the IL-1 haplotype. The results indicated that the IL-1 haplotype may be of limited value for the prognosis of periodontal disease progression following non-surgical periodontal therapy.

Protective effect of serum antibodies against a 110-kilodalton protein of Actinobacillus actinomycetemcomitans following periodontal therapy.

Thirty-four adult patients with untreated periodontitis were randomly assigned to receive full mouth scaling alone or scaling with an adjunctive antimicrobial therapy, both followed by supportive periodontal therapy. At 24 months, specific serum immunoglobulin A (IgA), IgG and IgG subclass antibody reactivities against a 110-kDa protein of Actinobacillus actinomycetemcomitans were assessed by Western blot. In patients harboring A. actinomycetemcomitans intraorally, the IgG4 antibody reactivity against the 110-kDa protein of A. actinomycetemcomitans was associated with significantly increased survival rates of teeth and of sites not exhibiting 2 mm or more of probing attachment loss. The same trend was found for IgG3 and IgG2 antibody reactivities, but it was statistically insignificant. No association with clinical treatment outcome was observed for IgA, IgG and IgG1 antibody reactivities. The results indicated that systemic IgG4 antibody reactivity against the 110-kDa protein of A. actinomycetemcomitans may have a protective effect against periodontal disease progression in patients harboring A. actinomycetemcomitans and receiving periodontal therapy.

Clonal infection with Actinobacillus actinomycetemcomitans following periodontal therapy.

Mechanical debridement results in a shift of the bacterial composition in the periodontal pocket on the species level. It is unknown, however, whether a clonal change within a species could lead to the emergence of strains with different levels of virulence. Therefore, in the present study, the genetic variability of Actinobacillus actinomycetemcomitans was assessed and strains identified which were associated with periodontal disease progression following periodontal therapy, i.e., refractory periodontitis. Twenty adult patients with untreated periodontitis and subgingival colonization of A. actinomycetemcomitans were randomly assigned to receive full-mouth scaling alone or scaling with an adjunctive antimicrobial therapy. Both groups received supportive periodontal therapy at 3, 6, 9, 12, 18, and 24 months. Subgingival plaque samples were taken at every visit; venous blood was obtained at 24 months only. A. actinomycetemcomitans isolates were typed by the RAPD method, and antibody reactivity against outer membrane proteins was assessed by immunoblot analysis. Eleven distinct RAPD patterns were found in 18 patients completing the study. All patients harbored only one A. actinomycetemcomitans genotype, and within each patient this genotype persisted throughout the 24-month observation period. No differences in the expression of antibody reactivity against outer membrane proteins were found between strains isolated at baseline and at 24 months. Three genotypes were associated with reduced survival rates of teeth without probing attachment loss of 2 mm or more. The results indicated that (i) most patients harbored only one A. actinomycetemcomitans genotype; (ii) the genotype persisted following therapy; and (iii) only some genotypes were associated with refractory periodontitis.

Erbium:YAG laser application in caries therapy. Evaluation of patient perception and acceptance.

OBJECTIVES: In previous studies it has been demonstrated that the Er:YAG laser can be used to prepare cavities efficiently and without thermal damage to the adjacent dental hard and soft tissues. To investigate the patients' response to Er:YAG laser preparation of teeth, a prospective clinical study was performed in five dental hospitals. METHODS: To evaluate patients' perception and response to cavity preparation a direct comparison was made between conventional mechanical preparation and Er:YAG laser preparation of caries in dental hard tissues. Half of the preparations were completed by the laser alone with standardized parameters, with the other half being mechanically prepared. The sequential order of treatment was randomized, and clinical parameters such as depth and location of the cavities were carefully balanced. A three-score evaluation scheme of patient responses was used: comfortable, uncomfortable, very uncomfortable. In addition the patients were asked to decide which was the more uncomfortable form of treatment and the preferred treatment for future caries therapy. RESULTS: The study included 103 patients with 206 preparations distributed amongst 194 teeth. All teeth gave vital responses (ice test) before and after both types of treatment. The laser treatment was found to be more comfortable than the mechanical treatment, with high statistical significance. During treatment, the need for local anaesthesia was 11% for mechanical preparation compared to 6% during laser application. It was found that 80% of the patients rated the conventional preparation as more uncomfortable than the laser treatment and 82% of the patients indicated that they would prefer the Er:YAG laser preparation for further caries treatment. CONCLUSIONS: The application of the Er:YAG laser system is a more comfortable alternative or adjunctive method to conventional mechanical cavity preparation.

Differential clinical treatment outcome after systemic metronidazole and amoxicillin in patients harboring Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis.

48 adult patients with untreated periodontitis harboring subgingival Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis as assessed by PCR were randomly assigned to receive full-mouth scaling alone (control) or scaling with systemic metronidazole plus amoxicillin and supragingival irrigation with chlorhexidine digluconate (test). In patients harboring A. actinomycetemcomitans intraorally at baseline, the adjunctive antimicrobial therapy resulted in a significantly higher incidence of probing attachment level (PAL) gain of 2 mm or more compared to scaling alone over 12 months (p<0.05). In addition, suppression of A. actinomycetemcomitans in subgingival plaque below detectable levels was associated with an increased incidence of PAL gain. In contrast, patients initially harboring P. gingivalis but not A. actinomycetemcomitans in the oral cavity showed a significantly higher incidence of PAL loss following adjunctive antimicrobial therapy compared to scaling alone (p<0.05). When the presence of pathogens at baseline was disregarded in the analysis, adjunctive antimicrobial therapy did not significantly enhance clinical treatment outcome. The results indicated that adults with untreated periodontitis harboring A. actinomycetemcomitans may benefit from the adjunctive antimicrobial therapy for a minimum of 12 months, whereas, the regimen may adversely affect the clinical treatment outcome of patients harboring P. gingivalis but not A. actinomycetemcomitans.

Working parameters of a magnetostrictive ultrasonic scaler influencing root substance removal in vitro.

This study assessed defect depth and volume resulting from root instrumentation using a magnetostrictive ultrasonic scaler with a slim scaling tip (P 12) in vitro. Combinations of the following working parameters were analyzed: lateral forces of 0.5 N, 1 N, and 2 N; tip angulations of 0 degrees, 45 degrees, and 90 degrees; power settings of low, medium, and high; and instrumentation time of 10, 20, 40, and 80 seconds. Defects were quantified using a 3-dimensional optical laser scanner. Lateral force had the greatest influence on defect volume compared to tip angulation and power setting (beta-weights 0.53+/-0.04, 0.17+/-0.04, and 0.19+/-0.04, respectively). Lateral force and tip angulation had similar effects on defect depth, but both effects were greater compared to power setting (beta-weights 0.43+/-0.04, 0.49+/-0.04, and 0.19+/-0.04, respectively). The various combinations of the assessed working parameters showed synergistic effects resulting in a wide range of defect depths (14.1+/-1.7 microm to 410.5+/-51.1 microm) and volumes (0.0084+/-0.0057 mm3 to 1.3+/-0.079 mm3). Severe root damage (defect depth >50 microm) at 40 seconds instrumentation time occurred under most combinations of lateral force, angulation, and power settings. The only exceptions were combinations of: 1) 0 degrees angulation, 0.5 N and 1 N lateral force at any power setting and 2) 45 degrees angulation, 0.5 N lateral force at low and medium power setting. The efficacy of the assessed magnetostrictive ultrasonic scaler may be adapted to the various clinical needs by adjusting the lateral force, tip angulation, and power setting.

Long-term maintenance of alveolar bone gain after implantation of autolyzed, antigen-extracted, allogenic bone in periodontal intraosseous defects.

This randomized controlled trial assessed the long-term maintenance of alveolar bone gain after implantation of autolyzed, antigen-extracted, allogenic (AAA) bone. AAA bone is a demineralized freeze-dried bone allograft processed after previously described methods. In each of 14 patients, AAA bone was implanted into the intraosseous defect of 1 tooth (test); a second tooth with an intraosseous defect was treated by modified Widman flap surgery alone (control). All patients were offered supportive periodontal therapy at 3- to 6-month intervals following treatment. Clinical measurements were taken prior to surgery, 6 months, and 3 years following surgery. Of the 14 patients enrolled, 11 patients completed the 6-month and 8 patients the 3-year examination. In test teeth, bone gain was significantly greater compared to control teeth at 6 months (2.2+/-0.5 mm and 1.2+/-0.5 mm, respectively) and 3 years (2.3+/-0.7 mm and 1.1+/-0.8 mm, respectively) (P < 0.05). Also, more probing attachment was gained in test compared to control teeth at 3 years (2.0+/-0.7 mm and 0.8+/-0.5 mm, respectively; P < 0.05). At 3 years, Porphyromonas gingivalis was detected in 3 test and 2 control teeth by polymerase chain reaction, whereas no Actinobacillus actinomycetemcomitans was found. Due to the low detection frequency, there was no clear correlation between the maintenance of alveolar bone during supportive periodontal therapy and subgingival infection with P. gingivalis. The data indicated that alveolar bone gain after implantation of AAA bone may be maintained over a minimum of 3 years in patients receiving periodontal supportive therapy.

The effect of working parameters on root substance removal using a piezoelectric ultrasonic scaler in vitro.

This study assessed defect depth and volume resulting from root instrumentation using a piezoelectric ultrasonic scaler with a slim scaling tip in vitro. Combinations of the following working parameters were analyzed: lateral forces of 0.5 N, 1 N, and 2 N; tip angulations of 0 degrees, 45 degrees, and 90 degrees; power settings of low, medium and high; and instrumentation time of 10 s, 20 s, 40 s, and 80 s. Defects were quantified using a 3D optical laser scanner. Overall, lateral force had the greatest influence on defect volume compared to instrument power setting and tip angulation (beta-weights 0.49 +/- 0.04, 0.25 +/- 0.04, and 0.14 +/- 0.04, respectively). The effects on defect depth were highest for tip angulation followed by lateral force and instrument power setting (beta-weights 0.48 +/- 0.04, 0.34 +/- 0.04, and 0.25 +/- 0.04, respectively). Interestingly, at all power settings, the highest defect volume and depth by far were found after combining 45 degrees tip angulation with 2 N of lateral force. The efficacy of the assessed piezoelectric ultrasonic scaler may be adapted to the various clinical needs by adjusting the lateral force, tip angulation, and power setting. To prevent severe root damage it is crucial to use the assessed scaler at a tip angulation of close to 0 degrees.

Differential effects of systemic metronidazole and amoxicillin on Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis in intraoral habitats.

48 adult patients with untreated periodontitis harboring subgingival Actinobacillus actinomycetemcomitans and/or Porphyromonas gingivalis were randomly assigned to receive full mouth scaling alone (control) or scaling with systemic metronidazole plus amoxicillin and supragingivai irrigation with chlorhexidine digluconate (test). Subgingival plaque and swab samples from tongue, tonsils, and buccal mucosa were taken at baseline, 10 days and 3, 6, 9, and 12 months. A. actinomycetemcomitans was detected in the oral cavity, i.e., subgingival plaque and/or mucous membranes, less frequently in test patients compared to controls at 9 and 12 months (p<0.01), whereas, the intraoral detection frequency of P. gingivalis was significantly reduced only 10 days following therapy (p<0.001). At any time after therapy, A. actinomycetemcomitans was not detected intraorally in 5 of 10 (50%) test and 1 of 13 (8%) control patients harboring this pathogen at baseline; P. gingivalis was not detected in only 1 of 18 (6%) test and none of the 17 control patients harboring this pathogen at baseline. Although the data indicated that the assessed antimicrobial therapy may suppress A. actinomycetemcomitans from the entire oral cavity below detectable levels over a minimum of 12 months, P. gingivalis persisted or reoccurred.

The effect of glass ionomer cement or composite resin bases on restoration of cuspal stiffness of endodontically treated premolars in vitro.

The purpose of the present study was to decide whether composite resin or conventional glass ionomer cement should be preferred as a base material in endodontically treated premolars. Twelve extracted human maxillary premolars were mounted in a universal testing machine at a 35 degrees angle. Cuspal stiffness was determined by applying a load of 75 N to the buccal cusp and recording the displacement of the cusp using inductive displacement transducers. In the same teeth, different cavity preparations and restorations were performed sequentially. Standard MOD cavities were enlarged to allow endodontic access. In addition, the cusps were undermined. Half of the teeth were restored to the level of the previous shallow cavities using conventional glass ionomer cement (Ketac Fil), in the rest of the teeth dentine bonding agent (Syntac) and composite resin (Tetric) were used instead. Finally, composite resin fillings (Tetric) were placed. All restorations were removed and the experiments were repeated twice. For each replication, the assignment of the base materials to the experimental groups was reversed, and ceramic inlays (Empress) were used as final restorations for the last replication. Improvement of cuspal stiffness achieved by conventional glass ionomer bases was very small, whereas composite resin bases increased cuspal stability by more than a factor of two. After placement of the final restorations, however, there was no longer a difference between teeth with different base materials. Nevertheless, composite resin bases might be preferred for two reasons. Firstly, deterioration of adhesive restorations will probably start at the cavosurface margins. The incidence of margin gaps, however, will not only compromise marginal seal but also the stabilizing effect of the restoration. In this situation, the resin base may still stabilize the tooth. Moreover, resin bases may reduce the risk of cusp fracture during the time between cavity preparation and the insertion of adhesive inlays.

Working parameters of a sonic scaler influencing root substance removal in vitro.

This study assessed defect depth and volume resulting from root instrumentation using a KaVo Sonic-flex Lux 2000 L sonic scaler with a slim scaling tip (Perio-Tip no. 8) in vitro. Combinations of the following working parameters were analyzed: lateral forces of 0.5 N, 1 N, and 2 N; tip angulations of 0 degree, 45 degrees, and 90 degrees; and instrumentation time of 10 s, 20 s, 40 s, and 80 s. Defects were quantified using a three-dimensional optical laser scanner. Instrumentation time had an almost linear impact on defect depth and volume. Although lateral force (beta-weight 0.55 +/- 0.062) had a greater influence on defect volume than tip angulation (beta-weight 0.29 +/- 0.062), their effects on defect depth were similar (beta-weight 0.43 +/- 0.052 and 0.50 +/- 0.052, respectively). The combination of force and angulation showed synergistic effects resulting in a wide range of defect depths (21.9 +/- 0.96 microns to 174 +/- 28.8 microns, at 40 s) and volumes (0.056 +/- 0.019 mm3 to 0.68 +/- 0.10 mm3 at 40 s). Severe root damage (> 50 microns/40 s) did not occur at any combination of 0.5 N lateral force and/or 0 degree tip angulation. By adjusting lateral force and tip angulation, the efficacy of the assessed sonic scaler may be adapted to various clinical needs.

Controlled local delivery of tetracycline HCl in the treatment of periimplant mucosal hyperplasia and mucositis. A controlled case series.

The purpose of this controlled case series was to assess the adjunctive efficacy of controlled topical tetracycline HCl application in the treatment of infection associated periimplant mucositis or mucosal hyperplasia. Eight patients with at least 2 endosseous implants showing clinical signs of periimplant mucosal hyperplasia or mucositis were enrolled. All implants received supra- and subgingival scaling, with half of the implants receiving adjunctive controlled local delivery of tetracycline HCl (test). Control implants did not receive any other therapy aside from scaling. Clinical parameters were assessed at baseline, 4, and 12 weeks. Scaling plus controlled local delivery of tetracycline HCl markedly reduced periimplant mucosal hyperplasia in 4 of 5 test implants and demonstrated a trend towards a reduction of bleeding on probing scores. Scaling alone had no effect on mucosal hyperplasia in the 2 control implants presenting with this condition nor bleeding on probing scores. In both groups, plaque index scores were slightly reduced at 4 weeks but returned to baseline values at 12 weeks, whereas pocket probing depths, clinical attachment levels, and probing bone levels remained unchanged during the course of the trial. The observed trends suggest that scaling plus controlled local delivery of tetracycline HCl may have beneficial effects. Randomized controlled trials employing a sample size high enough to reach sufficient statistical power are needed to definitively assess the efficacy of controlled local tetracycline HCl delivery on periimplant diseases.